I wrote two things, one two years ago, and one about a year ago about working hard, hours and balance. There's been lots of talk on the tweets about how hard people should work. As if should was a real thing. Here are the valuable bits (much more in each of these posts):

Firstest thing:

It's a worthwhile exercise to sit down and actually track the hours you really work. When I was in grad school a friend of a friend was a French woman (she impossibly old and chic and beautiful to me at the time), call her Martine, who had two little children, and was single by choice. Martine was doing a visiting postdoc in the US for 9 months to learn techniques. She absolutely worked only from 8 to 4. Everyone was aghast, and predicted doom and failure. But, I watched some, and talked to my friend some, and it was very clear that when Martine worked, she worked. She did had one cup of coffee at 10:30 or so in the morning. That was it. Lunch was at her desk reading. Martine did not avoid the social relationships that are part of what make a lab work, and the discussions about science. But she didn't go to the gym in the middle of the day, she didn't hang out on the lawn or play volleyball or talk about fashion or movies. She didn't surf the web, which was largely impossible as there was no web at the time.

What struck me at the time, and stayed with me these many years, was that this woman had made decisions about what was important to her, and what she was going to do, large and small scale.

“My dear, here we must run as fast as we can, just to stay in place. And if you wish to go anywhere you must run twice as fast as that. -- Lewis Carroll, Alice in Wonderland.

In evolutionary biology, this came to imply that if a species did not evolve, but stayed in place, it would go extinct, given that it was existing in an ever changing environment and competing with other species that were evolving.

In the cultural context of academic survival, it means that if there are fewer places (jobs or grants) than people who want them, one must run as hard as the others who also desire those ends. I am not saying this is A Good Thing, or that it is A Bad Thing. It is merely A Thing, and to a large extent, A True Thing. One's emotional response to this is, to a large extent, irrelevant. We can all commit to changing the system. We can work towards being different.

But, when you are a postdoc, or an untenured faculty, railing against this, tweeting furiously will not change the fact that if you want to succeed, you need to achieve standards.And those standards are often made in comparison to other people who are also running as hard as they can.

You can certainly find ways to only work 40 h/wk, especially as a student or postdoc. You just have to be smart about your time and only do experiments that will give conclusive results. A trainee's main job is to produce and curate publishable data. As long as you're doing that effectively, it doesn't matter how many hours you're putting in.

On the other hand, as a PI, I am never finished no matter how much I work. There's always another paper to edit, a review article to write, a rec letter to write, a thesis to read, grants to write, grants to review, new projects to think about, and on and on. And those are just the things I do in my "free time" when I'm not in meetings, class, or conducting experiments myself. I guess I'm lucky that I really enjoy spending time in coffee shops with my laptop, and that my partner is often there with me. I don't know how a PI with more demanding outside responsibilities could get it all done.

Damn right there's always something needs doing! Despite this, however, there are a couple of skills that can be invaluable to anyone in academia...

The first is learning how to say no.

The second is learning where to set a threshold for when to turn off. If I go home and there are more than a dozen or so actionable items left in my email in-box, I won't be able to relax at night knowing they're still there waiting for me next day. My threshold is about 10-12, but below that I'm OK just letting things wait. Above that, I start to feel bogged down and can't sleep. I know people with a threshold of 100, and others who will not let go until every last item is done.

The two skills are of course related, since a very effective way to prevent your to-d0 list from getting too long is preventing items from getting on there in the first place.

My advice for trainees. Look at the CV of several people who most recently got the type job you want, whatever that may be. In that ballpark is what you will need to be competitive. Then decide how hard and efficiently you will need to work to get your CV to that place. And finally, decide whether you can do that AND be happy in the other aspects of your life. If the answer is no, fair or not, it is time to consider alternatives.

Fair or not, some members of the search committee consider pedigree. So adjust upwards on pubs and grants if you think your pedigree puts you at a disadvantage. This is an exercise in your ability to evaluate your competitiveness for a position realistically.